Operating System

An Operating System (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. When you start using a Computer System then it's the Operating System (OS) which acts as an interface between you and the computer hardware. The operating system is really a low level Software which is categorised as a System Software and supports a computer's basic functions, such as memory management, tasks scheduling and controlling peripherals etc.

This simple and easy tutorial will take you through step by step approach while learning Operating System concepts in detail.

What is Operating System?

An Operating System (OS) is an interface between a computer user and computer hardware. An operating system is a software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers.

Generally, a Computer System consists of the following components:

• Computer Users are the users who use the overall computer system.
• Operating System - Examples

  There are plenty of Operating Systems available in the market which include paid and unpaid (Open Source). Following are the examples of the few most popular Operating Systems:

  • - Windows : This is one of the most popular and commercial operating systems developed and marketed by Microsoft. It has different versions in the market like Windows 8, Windows 10 etc and most of them are paid.
  • - Linux : This is a Unix based and the most loved operating system first released on September 17, 1991 by Linus Torvalds. Today, it has 30+ variants available like Fedora, OpenSUSE, CentOS, UBuntu etc. Most of them are available free of charges though you can have their enterprise versions by paying a nominal license fee.
  • - MacOS : This is again a kind of Unix operating system developed and marketed by Apple Inc. since 2001.
  • - iOS : This is a mobile operating system created and developed by Apple Inc. exclusively for its mobile devices like iPhone and iPad etc.
  • - Android : This is a mobile Operating System based on a modified version of the Linux kernel and other open source software, designed primarily for touchscreen mobile devices such as smartphones and tablets.

  Some other old but popular Operating Systems include Solaris, VMS, OS/400, AIX, z/OS, etc.

  Operating System - Functions

  To brief, Following are some of important functions of an operating System which we will look in more detail in upcoming chapters:

  • - Process Management
  • - I/O Device Management
  • - File Management
  • - Network Management
  • - Main Memory Management
  • - Secondary Storage Management
  • - Security Management
  • - Command Interpreter System
  • - Control over system performance
  • - Job Accounting
  • - Error Detection and Correction
  • - Coordination between other software and users
  • - Many more other important tasks
  Operating Systems - History

  Operating systems have been evolving through the years. In the 1950s, computers were limited to running one program at a time like a calculator, but later in the following decades, computers began to include more and more software programs, sometimes called libraries, that formed the basis for today’s operating systems.

  The first Operating System was created by General Motors in 1956 to run a single IBM mainframe computer, its name was the IBM 704. IBM was the first computer manufacturer to develop operating systems and distribute them in its computers in the 1960s.

  There are few facts about Operating System evaluation:

  • - Stanford Research Institute developed the oN-Line System (NLS) in the late 1960s, which was the first operating system that resembled the desktop operating system we use today.
  • - Microsoft bought QDOS (Quick and Dirty Operating System) in 1981 and branded it as Microsoft Operating System (MS-DOS). As of 1994, Microsoft had stopped supporting MS-DOS.
  • - Unix was developed in the mid-1960s by the Massachusetts Institute of Technology, AT&T Bell Labs, and General Electric as a joint effort. Initially it was named MULTICS, which stands for Multiplexed Operating and Computing System.
  • - FreeBSD is also a popular UNIX derivative, originating from the BSD project at Berkeley. All modern Macintosh computers run a modified version of FreeBSD (OS X).
  • - Windows 95 is a consumer-oriented graphical user interface-based operating system built on top of MS-DOS. It was released on August 24, 1995 by Microsoft as part of its Windows 9x family of operating systems.
  • - Solaris is a proprietary Unix operating system originally developed by Sun Microsystems in 1991. After the Sun acquisition by Oracle in 2010 it was renamed Oracle Solaris.
• - Application Softwares  are the softwares which users use directly to perform different activities. These softwares are simple and easy to use like Browsers, Word, Excel, different Editors, Games etc. These are usually written in high-level languages, such as Python, Java and C++.
• - System Softwares  are the softwares which are more complex in nature and they are more near to computer hardware. These software are usually written in low-level languages like assembly language and includes Operating Systems (Microsoft Windows, macOS, and Linux), Compiler, and Assembler etc.
• - Computer Hardware  includes Monitor, Keyboard, CPU, Disks, Memory, etc.